A glass tube of uniform internal radius `(r)` has a valve separating the two identical ends. Initially, the valve is in a tightly closed position. End `1` has a hemispherical soap bubble of radius `r`. End `2` has sub-hemispherical soap bubble as shown in figure. Just after opening the valve.

Options

A. air form end 1 flows towards end 2, No change in the volume of the soap bubbles
B. air from end 1 flows towards end 2. Volume of the soap bubble at end 1 decreases
C. no change occurs
D. air from end 2 flows towars end 1 .Volume of the soap bubble at end 1 increases

Answer

B

Explanation

Excess pressure in a soap bubble , ` dP = (4T)/r or dP prop 1/r`
The radius of the hemispherical soap bubble at the end (1) is less than that of the sub - hemispherical soap bubble at the end (2) . Excess pressure at the end 1 is more than that at the end 2 .
` :. ` Air from end 1 will flow the end 1 to end 2 and hence the volume of the soap bubble at the ebd (1) will decrease . This is option (b) .